English Reference
adjective · verb · noun

idle

adj. · v. · n.
US /ˈaɪdəɫ/ UK /ˈaɪdəl/ idle UK spelling idled, idles, idling

  1. 01 B2 Upper Intermediate

    adj.not being used or not working at the moment.

    adj.not in active use or operation; describing resources or machinery that are currently functional but unoccupied.

    Simple

    The machines in the factory stood idle during the long holiday weekend.

    In context

    The company struggled with the high costs of maintaining idle equipment while waiting for the new contracts to be signed.

  2. 02 B2 Upper Intermediate

    adj.lazy or not willing to work.

    adj.habitually avoiding work or exertion; lazy or slothful in character.

    Simple

    He was an idle student who preferred playing games to doing his homework.

    In context

    The manager warned that idle employees would not be considered for the year-end performance bonuses.

    lazyindolentslothful
    industrioushard working
  3. 03 C1 Advanced Formal

    adj.having no real purpose or value; silly.

    adj.lacking substance, utility, or a serious basis; often used to describe talk, threats, or curiosity.

    Simple

    She didn't want to waste time on idle gossip about her neighbours.

    In context

    The diplomat dismissed the rumours as idle speculation, insisting that no formal agreement had been reached.

  4. 04 B2 Upper Intermediate

    v.when an engine runs slowly while the vehicle or machine is not moving.

    v.to run at a low speed or out of gear; describing an internal combustion engine ticking over without performing work.

    Simple

    The taxi driver let the car idle while he waited for the passenger to come outside.

    In context

    Modern vehicles are often designed to shut off automatically rather than idle at traffic lights to improve fuel efficiency.

  5. 05 C1 Advanced Literary

    v.to spend time doing nothing or being lazy.

    v.to spend time in an inactive or lazy manner; often used with 'away' when transitive.

    Simple

    They idled away the afternoon sitting by the river and talking.

    In context

    He spent his inheritance idling away his youth in expensive resorts instead of pursuing a career.

    loiterloungedally
  6. 06 C1 Advanced Technical Technical

    n.the state of an engine when it is running but not moving.

    n.the lowest power setting or speed at which an engine can run steadily.

    Simple

    The mechanic adjusted the idle because the car kept stalling at red lights.

    In context

    The pilot reduced the engines to idle as the aircraft began its final descent toward the runway.

    low power

Rather, they were aimed at the easier target of idling vehicles – those whose engines are running for no real reason except that someone didn’t bother to turn them off.

The Conversation· 31 Jul 2026

Etymology 1

From Middle English idel, ydel, from Old English īdel, from Proto-West Germanic īdal, from Proto-Germanic īdalaz. Cognate with Dutch ijdel (“vain, meaningless”), ijl (“rareified, skinny”), iel (“thin, slender”); German Low German iedel (“vain, idle”); German eitel (“vain, conceited”); and possibly Old Norse illr ("bad"; > English ill).

Etymology 2

From Middle English idelen, from Old English īdlian, from Proto-West Germanic *īdalēn. Cognate with German eiteln (“to make empty, free up”).

Etymology 3

From Middle English idel, ydel, from Old English īdel (“idleness”), from the adjective (see above).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin gem-pro *īdalaz
Level B2 · Upper Intermediate
Frequency Frequent
Updated